Tool adapter

ABSTRACT

The invention is based on a tool adapter ( 30 ), for fastening a disklike tool ( 12 ) on a slaving device ( 16 ) of a hand power tool, that has a tool retention means ( 36 ) for connection to the tool ( 12 ).  
     It is proposed that the tool adapter ( 30 ) includes a fastening means ( 52, 54 ) for form-locking connection with the slaving device ( 16 ).

PRIOR ART

The invention is based on a tool adapter as generically defined by thepreamble to claim 1.

Rubber plates for fastening sheets of sandpaper To a power drill, forinstance, are known that are fastened in force-locking fashion in thechuck of the power drill. The sheet of sandpaper is retained on therubber plate by a larger slaving disk, which in turn is connected to therubber plate by a screw.

ADVANTAGES OF THE INVENTION

The invention is based on a tool adapter, for fastening a disklike toolon a slaving device of a hand power tool, that has a tool retentionmeans for connection to the tool.

It is proposed that the tool adapter includes a fastening means forform-locking connection with the slaving device. Tools can be connectedto the slaving device of the hand power tool and need not be adapted intheir design to the slaving device. For instance, a tool with a simplehub that has no special fastening means can be located on a slavingdevice with specially designed fastening elements. By means of the formlock, an especially stable retention of the tool adapter on the slavingdevice can be assured.

The tool adapter is prepared such that it can be secured to the slavingdevice of a complete hand power tool. The slaving device of the handpower tool is thus a tool slaving device. The tool adapter is thereforenot part of the hand power tool but instead is a separate component,independent of the hand power tool, and can be secured like a tool tothe slaving device.

The tool retention means is advantageously provided for force-lockingconnection to the tool, and as a result simple fastening of the tool canbe achieved. The tool can, in addition to the force lock, be retained byan additional form lock. The force lock is expediently effected in thetangential direction, while the additional form lock is effected in theaxial direction. The tool can be retained especially simply and yetfirmly and securely on the tool adapter. The tool retention means mayhave a threaded element, by which the force and form lock areestablished.

Expediently, the tool retention means includes a centering element. Animbalance of the tool during a machining operation can be counteracted.

In a further feature of the invention, it is proposed that the fasteningmeans is provided for form-locking connection in the tangentialdirection with the slaving device. A strong force moment can betransmitted to a rotating tool without requiring that the tool adapterbe chucked in force-locking fashion.

Advantageously, the fastening means is formed by a cup-shaped element. Arelatively large area for absorbing a strong driving force can be usedon the inner or outer wall of the cup-shaped element. Wear of thefastening means and hence of the tool adapter can be counteracted. Thecup-shaped element may be embodied with a cap or a partial cap, or itmay be embodied entirely without a cap, for instance in the form of ahollow-cylindrical element.

The tool adapter can be securely connected to the slaving device withoutchucking if the fastening means is provided for form-locking connectionwith the slaving device in the axial direction. In addition, a form lockwith the slaving device in the tangential direction may be provided. Anespecially secure form lock in the axial direction can be attained ifthe fastening means includes a retaining element, which can be graspedfrom behind in the axial direction. The retaining element thus has oneside facing away from the slaving device that can be braced in the axialdirection by a retaining means, which for instance is hook-shaped, ofthe slaving device. The retaining element is designed in particular inthe form of a segment of a circle, so that by a rotary motion of atleast part of the tool adapter it can be rotated underneath a retainingmeans of the slaving device. By this rotation, locking of the tooladapter in the axial direction on the slaving device can be attained.

A form-locking connection of the tool adapter with the slaving device,especially in the axial direction, can be attained in an especiallysimple way if the fastening means includes an opening through a plateelement that extends in the radial direction. A retaining means, guidedthrough this opening, of the slaving device can secure the plate elementand thus the tool adapter in the axial direction and expediently also inthe tangential direction by force-locking engagement. The main elementis platelike, at least in part, and is for instance a metal sheet.

By means of a centering element for centered mounting on the slavingdevice, an imbalance of the tool adapter during a machining operationcan be counteracted in a simple way. The centering element is forinstance a centering opening, particularly through the plate element,and as a result centering can be achieved even without a correspondingopening in the slaving device. The slaving device can be constructed incompact form.

Advantageously, the centering element has at least one recess in theradial direction. As a result, the tool adapter can be adapted to a codeon the slaving device, and an unambiguous association can be madebetween the tool adapter and a coded slaving device.

Suitability of the tool adapter for a fast-action chucking system can beattained by means of a pushbutton element located on one side of thetool. The pushbutton element can be operated from the side on which thetool is located on the tool adapter and is thus easily accessible. Bymeans of the pushbutton element, a release device in the slaving devicecan be actuated, and the tool adapter can be released from the slavingdevice in an especially simple way. The pushbutton element may have anysuitable shape and is a function element that is displaceable bypressure relative to its surroundings.

Expediently, the pushbutton element is located at least partly in thetool retention means. As a result, a central position of the pushbuttonelement in the tool adapter can be attained and hence an imbalance ofthe tool adapter can be counteracted.

Advantageously, the pushbutton element can be operated from one side ofthe tool, and on a slaving side diametrically opposite that side of thetool, it includes a function element. The slaving side, during a workoperation, is oriented toward the slaving device, and therefore theslaving-side function element can actuate a corresponding functionelement of the slaving device, such as a pushbutton element, directly orindirectly.

To avoid unintentional actuation of the pushbutton element, thepushbutton element has an operation element, which in the unactuatedstate is at least for the most part sunken in an indentation. Additionalsafety can be achieved by means of a spring element, which isprestressed for preloading the pushbutton element counter to anactuation direction.

Simple manufacture of the tool adapter can be attained by a first mainelement that includes the tool retention means and a second mainelement, separable from the first main element, that includes thefastening means. The tool retention means and the fastening means canthus be produced separately and connected firmly to one anotherindirectly or directly by means of suitable connection means for firmconnection of the two main elements, such as screws.

DRAWINGS

Further advantages will become apparent from the ensuing description ofthe drawings. In the drawings, one exemplary embodiment of the inventionis shown. The drawings, description and claims include numerouscharacteristics in combination. One skilled in the art will expedientlyconsider these characteristics individually as well and put themtogether to make useful further combinations.

Shown are:

FIG. 1, a right-angle grinder with a cutting wheel;

FIG. 2, a slaving device of the right-angle grinder;

FIG. 3, an exploded view of a tool adapter; and

FIG. 4, a main element of the tool adapter, with the cutting wheelsecured to it.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

FIG. 1 shows a right-angle grinder 2 from above, with an electric motor,not identified by reference numeral, supported in a housing 4. Theright-angle grinder 2 can be guided via two handles 6, 8. Via theelectric motor, a gear, not shown, in a gearbox 10, and a likewise notvisible driveshaft, a tool 12 embodied as a cutting wheel can be drivenin a tangential direction 14.

If the right-angle grinder 2 is viewed not from above as in FIG. 1 butrather from below and the tool 12 is removed, then a slaving device 16of the right-angle grinder 2 becomes visible. This slaving device 16 isshown in FIG. 2 in perspective, isolated from the other components ofthe right-angle grinder. The slaving device 16 includes a slaving flange18, a centering collar 20, three identical fastening elements embodiedas detent bolts 22, and three likewise identical fastening elements 24,embodied as clamping hooks. An actuation button 26 is located centrallyinside the centering collar 20. Three encoding projections 28 protruderadially outward from the centering collar 20.

FIG. 3 shows a tool adapter 30 with a first main element 32, shown atthe top in FIG. 3, and a second main element 34, shown below the firstmain element 32. A tool retention means 36, which includes a threadedelement 38 and a centering element 40, is a component of the first mainelement 32. A pushbutton element 42 is located partly inside the toolretention means 36; on a side toward the tool, it includes an actuatingelement 44, and on a slaving side it includes a function element 46. Theactuating element 44, for the sake of simple assembly, is screwed onto acentral core of the pushbutton element 42.

The second main element 34 includes a plate element 50 inside aconnecting flange 48; the plate element includes three first fasteningmeans 52, embodied as a cup-shaped indentation, and three fasteningmeans 54 each with one opening 56. A centering element 58 embodied as anopening is located centrally in the plate element 50 and has threeradial recesses 60, of which only one, however, is visible. For firmlyconnecting the two main elements 32, 34 to one another, the tool adapter30 includes four screws 62, each passed through a respective hole 64 inthe connecting flange 48 and screwed into a threaded bore 66 in thefirst main element 32. It is also possible for the two main elements 32,34, after their manufacture, to be connected by material engagement toone another, for instance by welding. Manufacturing the tool adapter 30in one piece is also conceivable.

The slaving device 16 shown in FIG. 2 is designed as a fast-actionchucking system, onto which tools can be fastened simply, quickly andsecurely with a tool hub designed to suit the plate element 50. Diskliketools such as grinding wheels, roughing disks, cutting wheels,sawblades, or the like of simple design, however, typically have only asingle circular centering opening and cannot be connected to the slavingdevice 16. It may be desirable, however, for even such simple tools tobe connected to the slaving device 16. To that end, the tool adapter 30is provided. The tool adapter 30 can be connected to the slaving device16 and can in turn itself receive simple disklike tools.

For connecting the tool adapter 30 to the slaving device 16, thecentering element 58 is slipped onto the centering collar 20. After itis slipped on, the plate element 50 rests on the three encodingprojections 28 and can now be rotated in the tangential direction 14,until the three recesses 60 cover the three encoding projections 28. Inthis position, the plate element 50—and with it the entire tool adapter30—drops somewhat lower, until it comes to rest on the three detentbolts 22. These three detent bolts 22 are spring-loaded and can bepressed downward by a user of the right-angle grinder 2 by pressure onthe tool adapter 30, until the tool adapter 30 rests on the slavingflange 18. As a result, the hook-like fastening elements 24 pass throughthe openings 56.

For fastening the tool adapter 30 to the slaving device 16, the plateelement 50 can now be rotated clockwise, as a result of which a radiallyinnermost region of the plate element 50 is moved underneath theencoding projections 28.

Simultaneously, a retaining element 68 of the fastening means 54,adjacent the respective openings 56 and embodied in the tangentialdirection parallel to an opening 56, is thrust beneath an obliquelyoriented ramp element 70 of the fastening element 24, whereupon thefastening element 24 is drawn upward somewhat along the force of aprestressed spring, not shown. A precise description of the slavingdevice 16, the spring-loaded detent bolts 22, and the fastening elements24 can be found in International Patent Disclosure WO 03/097299.

Upon further rotation of the plate element 50 and tool adapter 30clockwise, the retaining element 68 is thrust beneath a lug 72, orientedparallel to the slaving flange 18, which with the aid of the prestressedspring, not shown, presses the plate element 50 onto the slaving flange18. When a fastening position is reached, the detent bolts 22 come tocoincide with the cup-shaped fastening means 52 of the tool adapter 30and by racing upward snap into these fastening means 52. The plateelement 50—and with it the entire tool adapter 30—is now fixed in thecup-like fastening means 52 in the tangential direction 14 by the detentbolts 22 and in the axial direction by the spring-loaded fasteningelements 24 that engage the retaining elements 68 from behind.

The tool 12 can now be chucked on the first main element 32, located onthe tool side; the order in which the connections are made, of the toolto the first main element 32, of the first main element 32 to the secondmain element 34, and of the second main element 34 to the slaving device16, is arbitrary. The tool 12 is guided, by a centrally embodiedcentering opening, not shown, over the tool retention means 36 andplaced around the centering element 40. Next, a pressure element 74,embodied as a lock nut, shown in FIG. 4 is threaded with its femalethread onto the threaded element 38, specifically until the tool 12 isfirmly clamped between a base plate 76 of the main element 32 and thepressure element 74. Instead of a lock nut, some other clamping elementthat suitably cooperates with the tool retention means may equally wellbe used; the threaded element 38 may optionally be replaced by someother suitable element.

For applying the force required for tensing the pressure element 74, thepressure element 74 is embodied with a hexagonal outer shape, like atool nut, and can be retained by a wrench. To generate a necessarycontrary force, any spindle lock that may be present for the right-anglegrinder 2 can be actuated; this prevents slaved rotation of the slavingdevice 16. For cases in which the right-angle grinder 2 has no suchspindle lock, the main elements 32, 34 are each embodied with two flatfaces 78, which can likewise be engaged by a large wrench. Now the twowrenches can be rotated counter to one another about the faces 78 andabout the pressure element 74 until the pressure element 74 presses thetool 12 firmly against the base plate 76. The tool 12 is now secured tothe tool adapter 30.

For releasing the tool adapter 30 from the slaving device 16, the userof the right-angle grinder 2 can press the actuating element 44 in theaxial direction toward the gearbox 10 of the right-angle grinder 2, andas a result the function element 46 on the slaving side presses againstthe actuation button 26 of the slaving device 16. As a result, thedetent bolts 22 are pulled downward and out of the cup-shaped fasteningmeans 52. The tool adapter 30 can be rotated counterclockwise andreleased from the slaving device 16.

To prevent unintentional actuation of the pushbutton element 42, theactuating element 44 is sunk completely inside the pressure element 74.The pushbutton element 42 is furthermore prestressed in the axialdirection away from the gearbox by a spring element 80 embodied as aspiral spring, so that in operation, even if the tool adapter 30experiences strong impacts, the actuation button 26 will not be actuatedunintentionally by the weight of the pushbutton element 42 alone.

1. A tool adapter (30), for fastening a disklike tool (12) on a slavingdevice (16) of a hand power tool, that has a tool retention means (36)for connection to the tool (12), characterized by a fastening means (52,54) for form-locking connection with the slaving device (16).
 2. Thetool adapter (30) in accordance with claim 1, characterized in that thetool retention means (36) is provided for force-locking connection ofthe tool (12) in the tangential direction (14) and for form-lockingconnection of the tool (12) in the axial direction.
 3. The tool adapter(30) in accordance with claim 1, characterized in that the fasteningmeans (52) is provided for form-locking connection in the tangentialdirection (14) with the slaving device (16).
 4. The tool adapter (30) inaccordance with claim 1, characterized in that the fastening means (52)is formed by a cup-shaped element.
 5. The tool adapter (30) inaccordance with claim 1, characterized in that the fastening means (54)is provided for form-locking connection with the slaving device (16) inthe axial direction.
 6. The tool adapter (30) in accordance with claim1, characterized in that the fastening means (54) includes an opening(56) through a plate element (50) that extends in the radial direction.7. The tool adapter (30) in accordance with claim 1, characterized by acentering element (58) for centered mounting on the slaving device (16).8. The tool adapter (30) in accordance with claim 7, characterized inthat the centering element (58) has at least one recess (60) in theradial direction.
 9. The tool adapter (30) in accordance with claim 1,characterized by a pushbutton element (42) located on one side of thetool.
 10. The tool adapter (30) in accordance with claim 9,characterized in that the pushbutton element (42) is located at leastpartly in the tool retention means (36).
 11. The tool adapter (30) inaccordance with claim 9, characterized in that the pushbutton element(42) can be operated from one side of the tool, and on a slaving sidediametrically opposite that side of the tool, it includes a functionelement (46).
 12. The tool adapter (30) in accordance with claim 1,characterized by a first main element (32) that includes the toolretention means (36) and a second main element (34), separable from thefirst main element (32), that includes the fastening means (52, 54).